Improvement in burglar-alarms



UNTED STATES PATENT @Errea ROBERT N. WETHERILL, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 151,526, dated June 2, 1674; application tiled April '27, 1874.

To all whom lit may concern.:

Be it known that I, ROBERT N. WETHER- ILL, of Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Burglar-Alarms; and I do hereby declare the following` to be a full, clear, and exact description thereof, which will enable others skilled in the art to which my invention relates to make and use the same, reference being had to the accompanying drawing, forming part of this specification, in which- Figure lis a perspective view 5 Fig. 2, lon gitudinal sect-ion 5 Fig. 3, bottom view.

This device relates to that class of inventions known as burglar-alamns, to be used-by persons traveling, and for houses generally, the alarm-box being in the shape of a scalene triangle, and havin g a yielding bottom. A mechanical movement is placed upon the inside in such a manner that when the alarm is placed upon the floor behind a closed door, the bottom of the door, coming in contact with the top of alarnn' presses the same together enough to cause the mechanism to give the alarm to the occupants of the room, or it can be attached to a window-sash in such a manner as to cause the alarm to sound when the window is raised or lowered.

In the aceompanyin g drawing, A represents the top and sides of the box; A', yielding bottom. Yithin this box is placed the alarm movement, which consists of the gear-wheel a, spring a', ratchet I), verge b', pinion d, hammer d', and their respective shafts, and the bell C, the movement being attached to the under surface of the top. C', stop; e, spring, riveted to the under surface of the top, the opposite end resting upon the bottom. The

bottom A' is pivoted to the sides of the box at e in order that the bottom may not be forced too far into the. box, or drop down too far when handled. The pin D is placed in the end, working in a slot in the bottom, this governing the movement up and down.

The operation of my invention is as follows: Then the alarm is to be used it is wound up in the ordinary manner with a key. The door to the room having been closed, the alarm is placed upon the iioor in elose'proximity to the same. bottom comes in contact with the top of the alarm, forcing it down over the bottom, causing the stop C to-disengage the verge b', which allows'the movement to operate the hammer upon the bell and give the alarm. NVhen the pressure is removed from the top of the box the spring e forces the bottom back to its original position, the stop C engaging the verge b and stopping the alarm.

I am aware that there are lmrglar-alarms containing mechanical movements and having a wedge-shaped attachment operated by the door opening upon the same. I disclaim any intention as to such device; but

That I do claim is- In combination, with suitable alarm mechanism, the triangular or wedge-shaped box A, having yielding bottom A', whereby it is adapted to be operated in the manner and for the purpose specified.

The above specification signed by me this 22d day of April, A. I). 1874.

ROBERT N. VETHERILL.

Titnesses JosrAH B. BROWN, R. D. INGnnsoLL. 4

Vhen the door is moved open the- 

